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Changes in Ocean Temperature and Chemistry (V

Changes in Ocean Temperature and Chemistry (V

Changes in 6 and by L. Jeremy Richardson

arth’s ocean is vast—both in will deteriorate to the point at which they come into balance with each surface area (covering more than conditions are detrimental to shell- other (equilibrium). Importantly, E70 percent of ’s surface) and forming organisms and the marine food that the ocean and reach in volume (approximately 1.3 billion chain. Thus, it will threaten equilibrium does not mean that they cubic kilometers, or 310 million cubic and marine generally—with are not interacting—quite the contrary. miles). These are enormous figures. potentially large implications for human In fact, the atmosphere is constantly Given the size of the ocean, it is not systems and the world’s food supply. interacting with the surface layers of surprising that it plays a critical role in The ocean and atmosphere are the ocean. What this means is, in a the system. ­coupled, meaning that they interact state of dynamic equilibrium, the ocean This chapter examines how human with each other, and an action in and atmosphere are always exchanging activity—namely the ongoing release one leads to a reaction in the other. items, but the net balance of items lost of greenhouse gases (GHGs), most The ocean and atmosphere, like any and gained remains the same. Think importantly dioxide (CO₂)—is physical system, strive for dynamic about a bathtub that is filling: If the changing the ocean in a measurable way, equilibrium. The worddynamic is still running and you pull out and how these changes will ultimately means they are constantly changing the drain plug, water is running out affect and human society. If and that they exchange heat and of the tub while it’s still being added, emissions continue to grow, the ocean , like , until but the overall water level remains the

104 Changes in Ocean Temperature and Chemistry (v. 3) GRADE STANDARD EEI UNIT in the drink is released into the air. This process works in reverse just as well. Grade 3 3.3.c-e Living Things in Changing Environments As more and more CO₂ is pumped into the atmosphere, about a third Grade 4 4.3.b of it is absorbed by the world’s ocean, Grade 5 which helps to bring the system back into balance and reestablish that Grade 6 6.4.a; 6.4.d equilibrium state. 6.5.e

Grade 7 7.3.e Responding to Environmental Change and Ocean Temperature Grade 8 8.5.e The excess GHGs in the atmosphere 8.6.a are enhancing the well-known ;as these gases same. The tub, in this case, is in a state having on the ocean—temperature and effectively trap heat near Earth’s surface, of dynamic equilibrium. chemistry—and how they affect marine the atmosphere and Earth’s surface Human activities are throwing life and, ultimately, humans. absorb some of the extra heat, and this system out of balance, and the The dynamic exchange between the the ocean absorbs the rest. Actually, has yet to reach a atmosphere and the ocean includes the of the ocean is about new equilibrium state. Humans not only gaseous water vapor but also 1,000 times greater than that of the release GHGs primarily through the . In fact, the ocean has air. Since 1960, the ocean has taken burning of fuels such as , absorbed about 30 percent of the CO₂ up about 20 times more heat than the oil, and natural gas and also through emitted by human activity since the atmosphere (Bindoff et al. 2007). Heat . GHGs are being released beginning of the Industrial Revolution capacity is a measure of how much heat in such large numbers that they are (around 1750) (Sabine et al. 2004). If energy is needed to change an object’s changing the physical makeup of this process seems difficult for your temperature by a certain amount. both the atmosphere and the ocean. students to comprehend, have them Materials with high heat capacities— This is causing observed changes in consider their favorite carbonated such as water—require large amounts Earth’s climate. Here we will focus beverage. If left to the open air, it of heat to produce a small increase in on two particular impacts GHGs are eventually goes flat—the CO₂ dissolved temperature.

CHAPTER OVERVIEW

Human activities are affecting the ocean in unprecedented ways. Every Pictures of Practice: time we burn fossil fuels, we emit gases into the air that amplify our natural Melting 108 Greenhouse Effect. Since the 1800’s, our surface , as well Student Thinking: as land temperatures, have warmed on average. This warming of ocean Ideas About water contributes to rising sea levels, in addition to changing existing and Bases 112 marine ecosystems. Case Study: The ocean is also a major . This means that the ocean uptakes Reefs 113 carbon dioxide from the atmosphere. In fact, the ocean has absorbed up Student Thinking to 30 percent of the carbon dioxide emitted into our air since we started Climate and the Ocean 114 the wide-scale burning of fossil fuels during the Industrial Revolution. The uptake of carbon, however, is having potentially serious impacts on ocean life. Our ocean is becoming more acidic, and some organisms are struggling in the new environment—especially those that build shells of .

Changes in Ocean Temperature and Chemistry 105 ENHANCED GREENHOUSE EFFECT Observations confirm that this added heat is increasing average sea surface temperatures (SSTs). From 1850 to 2005, the average increase in SSTs per decade was about 0.04°C (Bindoff et al. 2007). Because the ocean is vast and has such a high heat capacity, it takes time for it to absorb the excess heat, meaning that there is a lag time between GHG emissions and observed change. This means that even if emissions stopped completely today, it would be several decades before the ocean reached equilibrium and the climate began to stabilize. Scientists have observed widespread changes in snow-and-ice cover around The increased amounts of GHGs, such as carbon dioxide (CO2), nitrous oxide (N2O), and (CH4) from increased use, are trapping more and the globe, and these changes have also more of the sun’s heat in our atmosphere. been attributed to human activities

RISING OCEAN AND LAND TEMPERATURES

TEMPERATURE ANOMALIES JANUARY–DECEMBER 2009

-5C -4C -3C -2C -1C 0C 1C 2C 3C 4C 5C Degrees Celsius

NOAA map of worldwide land and sea temperature anomalies (difference from the average temperature from 1971–2000). Areas in red were observed warmer than average; blue areas indicate that observed temperatures were cooler than average.

106 Changes in Ocean Temperature and Chemistry (as have temperature increases). A Teaching combination of increased temperatures Tip and increased melting has led to an observed rise in global average (Bindoff et al. 2007). Most of this Students commonly think that the melting , ice shelves, and other increase, possibly as much as 75 percent, oceanic ice will be the largest contributors to sea-level rise, but scientists is due to the of know differently. There is a simple activity to demonstrate why scientists the ocean. Your students may think are more concerned with melting glacial ice or ice that is on land than that sea-level rise from climate change with oceanic ice. Have students first think about a glass of ice water. Ask is only caused by melting icebergs. students, “If the ice melts, will the glass overflow?” Students will often say Physical objects expand as they warm yes, even though they have regularly seen evidence to the contrary. Then and contract as they cool, and water have them create a simple experiment to show otherwise: behaves the same way. (This is why Take two identical bowls or beakers—clear glass works best. Into each bowl, wooden doors sometimes and place something to represent land; another smaller bowl placed upside- stick in the middle of a hot summer and down works well. To each bowl add an identical amount of ice. In one bowl, why bridges have a metal connector at the ice goes onto the “land” to represent glacial ice. In the other bowl, the ice either end—so the bridge can expand goes around the land to represent oceanic ice. Then have students add water and contract without breaking.) to each bowl to an identical level. Have students draw a line on the outside of An important distinction must be the bowl at the water line—dry or wet erase markers work best. Next, let the made here between land ice and melt. Once all the ice has melted, have students measure which scenario ice. Land ice is ice that is on the land, showed greater water-level increase. The bowl with the land, representing a supported entirely by landmass. The glacial-ice situation, should have risen substantially higher than that with the most important land-based ice sheets oceanic ice. Have students think about and discuss what this might mean for are in and . Sea global climate change and our ocean. ice, on the other hand, is floating in ocean water—the sea ice that covers the North Pole in the Basin is a good example. As sea RISING SEA LEVELS ice melts, it has important consequences for warming because the ocean absorbs most of the incoming light energy from the sun, while the bright snow and ice reflect most of the light. But melting sea ice does not affect sea level at all. Land- based ice, when it melts and flows into the ocean, raises sea level. As a frame of reference, if both the Greenland and West Antarctic ice sheets were to collapse and melt completely, global average sea level would rise about six or seven meters (20 to 23 feet)! In contrast, when Arctic sea ice undergoes seasonal melting, sea level does not increase at all. Fortunately, although significant losses are possible, most scientists think The red curve shows reconstructed sea-level fields since 1870; the blue curve shows coastal -gauge measurements since 1950; and the black curve a complete collapse is unlikely. is based on altimetry, which measures height. The curves indicate The ocean has also experienced deviations from average sea level. Reproduced from Figure 5.13, IPCC AR4 changes in , or saltiness. As WGI, p. 410. discussed in Chapter 1, temperature

Changes in Ocean Temperature and Chemistry 107

Melting Ice

tudents have likely heard about melting polar ice and threats to polar wildlife caused by climate change. In the last decade, we have S witnessed unprecedented melting of our polar ice. Data from NASA scientists show that Arctic sea ice has decreased substantially from the long-term average, and Antarctica is also losing ice mass in certain regions, although there is more uncertainty about Antarctic melting compared to Arctic melting (for more information visit http://climate.nasa.gov/). Students may have questions about what will happen as this ice melts and enters other systems on Earth.

Students: Grade 8 Classroom Context Location: San Marcos, California Ms. Brice taught an extensive unit on climate change to her eighth-grade (a coastal community) students; content especially focused on current research on changes in the Goal of Video: The purpose of ocean system. This lesson was the first in the unit to bring up melting polar watching this video is to listen ice. The interviews occurred only two days after the lesson. to student ideas about melting ice in different polar regions and Video Analysis outcomes of melting ice on the ocean and climate. In this video students are wrestling with possible outcomes of melting polar ice. As polar ice caps melt, scientists are concerned with outcomes of , freshwater entering our ocean and how this will impact sea level and ocean currents. Ice in the Arctic is mostly sea ice (save the massive covering Greenland). The ice in Antarctica is mostly covering land. The melting of ice on land will influence sea level more than melting sea ice. But the melting of sea ice in the Arctic has another disturbing consequence—the potential to change, or halt, our ocean currents as dense, cold, freshwater enters our northern ocean (http://science.nasa.gov/science-news/science-at-nasa/2004/05mar_arctic/). Changing water temperature, chemistry, and density from melting polar ice may impact our ocean currents, which could also affect the movement of air masses, especially in the northern Atlantic. In this video, Ms. Brice teaches about the difference between melting sea ice in the Arctic compared to melting ice sheets in Greenland and Antarctica. The class talks about the percentage of an that is visible above sea level. After some discussion, the class agrees that the answer is approximately 10 percent. Once the class has understood the concept of sea ice versus ice on land melting, students explain the possible consequences of melting ice in their interviews. The class then discusses what will happen if cold, dense water enters the ocean. Listen as students describe the possibility of another . What did they understand and not understand from the classroom discussions?

Reflect What would be your next step to teach about melting ice and the ocean system? What did students seem to understand and not understand during their interviews? What were the most important misconceptions? Given that these students have had some, but limited, discussion on the topic, what additional activities and discussions could you do with students?

108 Changes in Ocean Temperature and Chemistry and salinity play an important role in Teaching the circulation of the ocean. Combined Tip with changes in temperature, this phenomenon has raised concerns about the effects on ocean circulation. Why does it take so long for the and atmosphere to reach Water moves in currents in the ocean, equilibrium? Students may not understand that even if GHG emissions not only along the surface but also stop completely, the climate will continue to change for decades because from the surface to the deep ocean. the ocean takes a long time to absorb all the excess heat. Show students This movement happens because of two clear glasses or cylinders of different sizes filled with water. Add the temperature and salinity of the 10–15 drops of food coloring to each one and ask students to guess which water—colder and saltier water is more one will mix faster. Have them watch while the small cylinder quickly dense, and dense liquids sink below less dissipates the food coloring, and the large cylinder takes much longer. dense liquids. This worldwide current Explain that when things are added to larger bodies of water, it takes a is called the , longer time for them to be completely absorbed. Once they grasp the or the ocean conveyor belt. Some effect on the small scale, it makes explaining why it will take so long for scientists believe that freshwater from the ocean to absorb the additional carbon dioxide and heat easier. melting ice sheets, when added to the ocean, will decrease salinity and disrupt thermohaline circulation. So far there is no convincing evidence that climate storms draw energy in part from believe that we can expect an increase in change has altered ocean currents, but it warmer . Models suggest that cyclone intensity but a decrease in the remains a concern for the future. higher maximum speed combined number of storms overall in a warmer Scientists are also concerned about with higher maximum rainfall averages climate. Higher sea levels and greater how changes in the ocean will affect may result in an increase of stronger wind speeds will also increase the other aspects of the climate system. storms. The jury is still out on the amount of ongoing coastal but Higher SSTs, for example, could lead ultimate impact on hurricanes due to would be of particular concern during to stronger hurricanes because these climate change, but generally, experts strong storms.

GLOBAL OCEAN CURRENTS

The ocean is in constant motion—driven by surface , controlled by water temperature and density, and guided by landmasses—to create an enormous conveyor belt effect.

Changes in Ocean Temperature and Chemistry 109 Climate Change and Teaching As noted earlier, in addition to warming, Tip the ocean is absorbing a significant fraction of the CO₂ emitted by human A simple way to demonstrate how water can absorb carbon dioxide is to activities. This is changing the chemistry have students exhale into a lidded cup of water. Have them check the pH of the ocean. When the ocean dissolves of the water before they begin blowing, and then again after 2–3 minutes, atmospheric CO₂, carbonic is and again after 5–6 minutes. Have them see how quickly they are able to formed. As a result, becomes change the pH of their water. (Note: to ensure proper hygiene, have each more acidic. This is calledocean student use a separate straw to blow into the cup.) acidification. As the oceans absorb CO₂, the dissolved CO₂ reacts with water (H₂O) to form (H₂CO₃). the atmosphere than an equivalent carbonate, and reducing the number of Carbonic acid is relatively unstable volume of freshwater in a or a . carbonate in the seawater. and breaks down into a ions, the other product of It’s important to clarify that this (HCO₃-) and a hydrogen ion (H+). the conversion process, make seawater process will not lead to the ocean The conversion of CO₂ to bicarbonate more acidic; as the concentration changing completely to an acid. The removes a CO₂ from the of hydrogen ions increases, the pH term acidification refers to the relative seawater solution, making room for decreases. Some of the free hydrogen change in the acidity levels of the ocean. another atmospheric CO₂ molecule ions react with carbonate ions to Although the pH is decreasing through to dissolve; this property of seawater form more bicarbonate ions, shifting this process, the ocean will remain basic, allows it to absorb more CO₂ from the balance to favor ­bicarbonate over or above 7.0 on the pH scale. However, organisms in the ocean are adapted to pH SCALE very specific conditions, and even small changes in pH can lead to major impacts. is measurably changing the pH of seawater. The ocean before the start of the Industrial Revolution had a pH of about 8.1 or 8.2, depending on latitude (Caldeira and Wickett 2005). So far, the pH of the ocean has declined by about 0.1 unit (Bindoff et al. 2007). That may not sound like much, but it represents a 26 percent increase in acidity! With continued emissions of CO₂, this situation will continue to worsen. Mid-range projections for emissions suggest that ocean pH could decline by another 0.3 or 0.4 unit by 2100, and that figure could be as high as 0.7 unit by 2300 for higher emission trajectories (Bindoff et al. 2007; Caldeira and Wickett 2003). These changes in ocean pH could dramatically impact some forms of The pH scale measures how acidic a substance is and ranges from 0 to 14. marine life—particularly those that Seawater has an average level of 8; even the slightest deviation can have depend upon the availability of calcium adverse affects on marine life. carbonate to make shells or skeletons

110 Changes in Ocean Temperature and Chemistry (called ). These organisms carbonate—and these species are so include , mollusks such as clams pervasive that they form the of the and , and some marine . Facing increased (e.g., ). As the ocean stress from more acidic waters, they becomes more acidic, there is less could decline or disappear, which would in seawater for these affect larger animals that feed on them organisms to use in building shells. If and thus potentially lead to ripple effects the ocean becomes acidic enough, living throughout the ocean food chain. calcified organisms can actually begin to Because colder water contains less In more acidic ocean waters, calcium dissolve. There is observational evidence carbonate shells of organisms like carbonate, the waters around Antarctica that more acidic waters may already this swimming pteropod, Limacina already have the lowest concentrations be affecting certain animals in some helicina, may be reduced. of carbonate worldwide. Projections regions; one species of microscopic indicate that by the 2030’s, seawater plankton in the ocean waters around acidification—so much so that it is there may become acidic enough to Antarctica has modern shell weights corrosive to baby oysters, which cannot dissolve the shells of some marine life 30–35 percent lower than those of the survive the higher acidity levels. Surface in the winter. This is a problem because past found in ocean (Moy et waters in a region near the California- some important species of plankton al. 2009). Oregon border, not too far from the have larval development stages in the Although results are preliminary oyster hatcheries, reached record-low pH winter; if waters are too acidic in that and research is ongoing, the recent levels of 7.75 in 2007 (Feely et al. 2008). season, it could disrupt the food chain collapse of the appears Ocean acidification may affect in the waters around Antarctica. to be connected to ocean acidification. other and commercial Although there will be winners and Beginning in 2005 and continuing fish species, particularly in coastal losers under ocean acidification, it in 2006, 2007, and 2008, two of the ecosystems and , which may is clear that these changes in ocean largest oyster hatcheries in Washington be more susceptible to changes in pH. chemistry will radically alter marine State reported production rates falling Experiments on the edible mussel environments. by about 80 percent (Miller et al. and the Pacific oyster (both species Finally, ocean acidification could have 2009). One hypothesis is that more important to global seafood production) direct effects on human society through acidic seawater from the deep ocean show that these organisms are very impacts on fisheries and . is upwelled into coastal areas. This sensitive to pH—they have a much more Globally, fisheries produce about 15 happens because, as winds force surface difficult time building their shells in a percent of the animal protein consumed waters away from the , it allows more acidic environment. by 2.9 billion humans, employ nearly deep waters to well up from below. The Plankton are a form of marine life that 200 million people directly and amount of CO₂ contained in the deep encompass a variety of different species. indirectly, and generate some $85 billion water has increased because of ocean Some of them form shells from calcium annually (UN Food and Organization 2008). Declining harvests, leading to loss of revenues from Teaching shellfish (and their predators), therefore, Tip represent measurable economic losses. In the United States, where domestic commercial fisheries contributed some To demonstrate the relationship between acidity and its ability to $34 billion to the U.S. GNP in 2007, dissolve chalk, you can use cups or beakers of water at varying acidities economic costs (in the form of revenue (this can be accomplished by blowing into the cups or by adding declines and job losses) due to ocean vinegar), and placing a small piece of chalk or a small shell into each acidification could be large, as mollusks, cup. Have students record how quickly or slowly the chalk dissolves at , and predators that feed on each pH. (Note: Dustless chalk will not easily dissolve in vinegar.) these species make up a sizable fraction of the industry (Cooley and Doney 2009).

Changes in Ocean Temperature and Chemistry 111

Ideas About Acids and Bases

tudents are often challenged by concepts that involve chemistry and pH. Introducing students to the general concepts of acids and bases and the pH scale is a good place to start, but also allowing students S to safely explore everyday items around them can be helpful as well. Scenario Your students have just completed a pH-indicator test on some common grocery store items such as peppers and oranges. After testing the pH, you ask your students if they have any questions about acids and bases.

Question What questions do you have about acids and bases after this experiment?

Scientific Answer pH is a measure of the hydrogen concentration in a solution. A lower pH indicates an acid, and a higher pH indicates a base. Items that test to the extremes of either side of the scale (below 3 or above 10–11) can be very harmful because highly acidic items have too many hydrogen ions (H+) and highly basic items have to many - hydroxyl ions (OH ). Water (H2O) is pH 7, or neutral, because it has equal amounts of hydrogen and hydroxyl ions. Many common food items will not cause grave harm to humans but will test moderately acidic or basic on the pH scale.

Student Answers Anna: I get why acids are bad, but then why are bases bad too? Roberto: Why can we touch some stuff that’s acid and not others? Greg: My mom won’t let me have soda, and I think it’s because it’s too acidy. Malia: I’m not going to eat lemons anymore cause they are an acid.

What Would You Do? How would you respond to Anna and Roberto’s questions in upcoming lessons?

How would you alleviate Greg and Malia’s misconceptions about foods that test weakly or moderately acidic?

Given these misconceptions, what challenges would you expect when teaching about ocean acidification.

The ocean is a critical component of as have sea surface temperatures. The and recreational activities, interrupt Earth’s climate system, and despite its acidity level of the ocean has increased the ocean’s natural food chain, disrupt vast size, it does respond to external by about 26 percent. These changes Earth’s , and contribute to forces. Human activities that release large can negatively impact some marine the decline of fisheries, thus, threatening quantities of GHGs (particularly CO₂) organisms that make shells from the world’s food supply. Therefore, global are now demonstrably changing the calcium carbonate. Such fundamental climate change can be viewed as a threat physical and chemical properties of the changes would harm of to the ocean, our economies, and our ocean. has increased, marine ecosystems, reduce tourism overall well-being.

112 Changes in Ocean Temperature and Chemistry Coral Reefs

oral reefs are important ocean and offer a compelling case of the risks of climate Cchange. Reefs provide a large fraction of Earth’s biodiversity—they have been called “the rain forests of the .” Scientists estimate that 25 percent of all marine species live in and around coral reefs, making them one of the most diverse habitats in the world. Paulo Maurin, education and fellowship coordinator for NOAA’s Conservation Program, says the reefs are invaluable to our planet’s biodiversity. “They act as productive nurseries to many fish species, warms, zooxanthellae are expelled from a coral’s tissue, giving the small fish a home and a chance to grow,” he causing it to lose its color and a major source of food. says. “Coral reefs’ diversity is so rich that we do not have This process is known as . a firm count on all the species that live within it and every Coral bleaching does not always mean the death of a discover new species.” coral reef. Corals can recover their zooxanthellae in time Reefs provide a variety of economic benefits, including but require cooler temperatures to do so. recreational activities, tourism, coastal protection, Warmer ocean water also becomes more acidic. Ocean for commercial fisheries, and preservation of acidification is making it more difficult for corals to build marine ecosystems. their hard . In ’s , “Corals are important to us for many reasons,” Maurin coral calcification has declined 14.2 percent since 1990— says. “From a practical point of view, they can help a large, rapid decline that hasn’t been seen for 400 . protect coastlines from storm events, for instance, and The combination of rising ocean temperatures and help maintain fisheries that are essential to a lot of increased acidity will likely cause major changes to coral people. And complex compounds found in coral reefs reefs over the next few decades and centuries. hold promises in modern medicine. These are what we Maurin believes there are several ways people can help call services that would be very difficult and preserve these valuable resources. expensive to replace. “Over the long term, we need to reduce the amount “They also have a unique ability to inspire us to of CO2 that is up in the atmosphere that is causing explore and visit the ocean. Can you think of any other both increased bleaching and acidification,” he says. invertebrate that people would come from afar just to “But in the more immediate time, there is other ways to see?” help. By understanding that bleaching and acidification Corals live with in a type of relationship called stress corals, we can help by building up what we call . This means the organisms cooperate with ‘reef resiliency.’ That is, making sure that reefs have this each other. The algae, called zooxanthellae, live inside capacity to bounce back. the corals, which provide a tough outer shell made from “For instance, ensuring that there is less calcium carbonate. In return for that protection, the entering the ocean can help far-away corals. Also, people algae provide their host with food produced through can help by making sure that the seafood consumed . Zooxanthellae also provide corals with is sustainable and not contributing to a depletion of their striking colors. fish species that keep algae in check, following fishing This symbiotic relationship is strongly dependent on regulations when fishing as well as supporting marine the temperature of the surrounding water. As the water protected areas in key conservation sites.”

Changes in Ocean Temperature and Chemistry 113

Climate and the Ocean

tudents’ understanding of global climate change as it relates to the ocean is tightly coupled with their understanding of the ocean itself. While students are often excited and engaged when learning about the S ocean, they may still harbor many misconceptions and misunderstandings about the ocean itself that can hinder their overall understanding of the ocean and global climate change.

Common Student Idea Scientific Concept

Temperature The ocean is already a warm place so When students go swimming at the ocean, global climate change is going to lead to it they are often swimming in warm near- becoming really hot, maybe even boiling. shore areas, but the majority of the ocean is relatively cold. Global climate change only needs to warm the ocean by a few degrees before major impacts are felt.

Warmer waters are good for animals. In fact, many ocean organisms are adapted to cooler waters. Cooler waters are often more productive because they contain nutrients upwelled from below.

Biodiversity If global climate change happens, all Studies are already showing that some the animals in the ocean will die. species will thrive under the new conditions, especially gelatinous animals (e.g., sea jellies).

Currents Currents will be the same; they’ll just Many currents are driven by temperature, be warmer. salinity, and density differences. A changing climate can alter all of these, thereby altering the currents.

Migration Animals can just move someplace new Some ocean animals are capable of if the ocean gets too hot or there isn’t migrating to new ranges but not all of enough food. them. Some animals are sessile (don’t move) as adults. It might take those species a while to adjust, as their larvae are the ones helping to expand their range.

Ask Your Students How much warmer will the ocean need to be before the effects are felt by fish?

Why might some animals thrive during climate change?

How long does it take for animals to adapt to changes in their environment?

114 Changes in Ocean Temperature and Chemistry

References

Bindoff, N. L., J. Willebrand, V. Artale, A, Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quéré, S. Levitus, Y. Nojiri, C. K. Shum, L. D. Talley, and A. Unnikrishnan. “Observations: Oceanic Climate Change and Sea Level.” Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H. L. Miller (eds.)]. Cambridge, United Kingdom and : Cambridge University Press, 2007..

Caldeira, K., and M. E. Wickett. “Anthropogenic carbon and ocean pH.” 425.6956 (2003):365.

Caldeira , K. and M. E. Wickett. “Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean.” J. Geophys. Res 110(2005):C09S04.

Cooley, Sarah R., and Scott C. Doney. “Anticipating ocean acidification’s economic consequences for commercial fisheries.” Environmental Research Letters 4.2 (2009):024007.

De’ath, G., J. M. Lough, and K. E. Fabricius. “Declining Coral Calcification on the Great Barrier Reef.”Science 323.5910 (2009):116.

Feely, R. A., C. L. Sabine, K. Lee, W. Berelson, J. Kleypas, V. J. Fabry, and F. J. Millero. “Impact of anthropogenic CO₂ on the CaCO₃ system in the oceans.” Science 305.5682 (2004):362–366.

IPCC. “Summary for Policymakers (WGI).” Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press, (2007).

Miller, A. W., A. C. Reynolds, C. Sobrino, and G. F. Riedel. “Shellfish Face Uncertain Future in High CO₂ World: Influence of Acidification on Oyster Larvae Calcification and Growth in Estuaries.”PLoS ONE 4.5 (2009).

Moy, A. D., W. R. Howard, S. G. Bray, and T. W. Trull. “Reduced calcification in modern planktonic .” Nature Geosci 2.4 (2009):276–280.

Pew Center on Global Climate Change. “The Science and Consequences of Ocean Acidification.” Arlington, VA. 2009. http://www.pewclimate.org/brief/ocean-acidification/Aug2009.

Raven, J., K. Caldeira, H. Elderfield, O. Hoegh-Guldberg, P. Liss, U. Riebesell, J. Shepherd, C. Turley, and A. Watson. “Ocean acidification due to increasing atmospheric carbon dioxide. Policy document 12/05.”The Royal Society, London.2005:57.

Sabine, C. L., R. A. Feely, N. Gruber, R. M. Key, K. Lee, J. L. Bullister, R. Wanninkhof, C. S. Wong, D.W.R. Wallace, and B. Tilbrook. “The oceanic sink for anthropogenic CO₂.”Science 305.5682 (2004):367–371.

UN Food and Agriculture Organization. “The State of the World’s Fisheries and .” 2008.http://www.fao.org/ docrep/011/i0250e/i0250e00.HTM.

Teaching Resources

California Education and Environmental Initiative resources: http://www.calepa.ca.gov/Education/EEI/default.htm

Natural Research Defense Council acidification lab kit:www.nrdc.org/oceans/acidification/files/labkit.pdf

National Geographic’s ocean acidification page:http://ocean.nationalgeographic.com/ocean/critical-issues-ocean-acidification/

National Geographic’s sea temperature rise page: http://ocean.nationalgeographic.com/ocean/critical-issues-sea-temperature-rise/

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